GitHub - mplsllc/macsurf: A modern web browser for Classic Mac OS 9 PowerPC. Real CSS3, ES5 JavaScript, native HTTPS — built with CodeWarrior on the Carbon API. · GitHub

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mplsllc/macsurf

 masterBranchesTagsGo to fileCodeOpen more actions menuFolders and filesNameNameLast commit messageLast commit dateLatest commit History830 Commits830 Commits.github/ISSUE_TEMPLATE.github/ISSUE_TEMPLATE  .vscode.vscode  browserbrowser  buildsbuilds  docsdocs  forclaudeforclaude  imgimg  macLinkmacLink  proxyproxy  screenshotsscreenshots  scriptsscripts  teststests  toolstools  .gitignore.gitignore  Access Paths.xmlAccess Paths.xml  CLAUDE.mdCLAUDE.md  CODE_OF_CONDUCT.mdCODE_OF_CONDUCT.md  CONTRIBUTING.mdCONTRIBUTING.md  CSS_IMPLEMENTATION_PLAN.mdCSS_IMPLEMENTATION_PLAN.md  CSS_SUPPORT_MATRIX.mdCSS_SUPPORT_MATRIX.md  GEMINI.mdGEMINI.md  LICENSELICENSE  MacSurf.sitMacSurf.sit  README.mdREADME.md  SAFETY_REPORT.mdSAFETY_REPORT.md  SECURITY.mdSECURITY.md  mactrovesource.txtmactrovesource.txt  puffpuff.pngpuffpuff.png  View all filesRepository files navigationREADMECode of conductContributingLicenseSecurity

The modern web, on a 25-year-old Mac.

MacSurf is a web browser for Classic Mac OS 9 PowerPC. CSS3, ES5 JavaScript, PNGs with alpha, running on a G3 iMac.

WarningMacSurf is early alpha. It runs, it renders, it talks TLS 1.2 natively to real HTTPS sites (as of May 2026), and it executes JavaScript on a 233 MHz G3. That doesn't mean it's ready for daily driving — most of the modern web still won't work in it. Heavy SPAs, modern CSS features we haven't shipped, missing form interactions, slow JS on real hardware. Plenty is rough.
But it's ready for people to try. If you've got a Power Mac G3 or G4 sitting around, please load it and see what breaks. Bug reports and screenshots from real hardware are exactly what this project needs. Contributors welcome too — there's a lot of CSS, DOM, and JS surface left to fill in, and the code is plain C89 (the same C you'd have written in 1999). See docs/status.md for the current punch list.
What you can expect: hand-built pages, retro-style sites, a respectable chunk of CSS Grid, native HTTPS with the full Mozilla CA bundle, and the strange thrill of running ES5 JavaScript on a PowerPC. What you shouldn't expect yet: smooth browsing on arbitrary modern sites, video, audio, WebGL, service workers, anything heavy on React.
First numbered release was 0.1a1 in May 2026. Latest is v1.3.1 — Forward, refined (2026-05-29): multi-curve ECDHE in TLS 1.3. macTLS now offers X25519, secp256r1 (P-256), and secp384r1 (P-384) in supported_groups, with HelloRetryRequest handled cleanly so servers that mandate a NIST curve can drive the rekey. That unblocks 68kmla.org — one of the largest active Classic Mac communities, XenForo on nginx with NIST-only curve config — which now renders fully on a G3 iMac via TLS 1.3 + P-384. Predecessor v1.3 — Forward landed the first native TLS 1.3 implementation on Classic Mac OS, ever — RFC 8446 handshake on BearSSL primitives, ChaCha20-Poly1305 + AES-128-GCM, verified end-to-end on a G3 iMac by Cloudflare's /cdn-cgi/trace, Akamai, BrowserLeaks, and How's My SSL. The day before, v1.2 — Sealed closed the documented insecure-stub entropy hole with macEntropy v1.0, wired POST forms through both fetchers, and shipped a real download manager. Full v1.3.1 notes in docs/release-notes/MacSurf-1.3.1.md. Predecessors: v1.3 notes, v1.2 notes, v1.0 notes.

Why this exists
The web outgrew Classic Mac OS twenty years ago. Modern HTTPS finished it off around 2016. Pull a G3 or G4 out of the closet today and it can barely reach a single live website.
MacSurf is an attempt to fix that on the machine itself — no screenshot proxy, no remote terminal trick. A native browser, built with the tools that were already on the platform: CodeWarrior, Carbon, QuickDraw, Open Transport. Real CSS3 layouts and real JavaScript, running inside the 64 MB memory floor of a 1999 iMac. Since late May 2026 it speaks TLS 1.2 directly to the modern web through macTLS, a BearSSL-based stack that ships inside the browser binary with 121 trust anchors from the Mozilla CA bundle. No proxy needed anymore.
As far as we can tell, this is the first serious NetSurf port to Classic Mac OS, and the first browser ever shipped on Mac OS 9 with native CSS Grid, CSS custom properties, and ES5 JavaScript.

The progression
Each shot below is a real milestone, captured on a Power Macintosh G3 running Mac OS 9. The fix-number annotations match this repo's commit history.

v0.2: JavaScript on Mac OS 9
First real-world JS-bearing page. Duktape 2.7.0 ES5 evaluating live: Math.sqrt, JSON, ES5 array methods.

fixes73: CSS transforms
Native transform: rotate() / scale() / translate(). Integer Q15 sin/cos table, no FPU dependency, arbitrary angles on QuickDraw.

fixes74d: radial gradients
2-stop radial gradients via concentric PaintOval stack. 16 levels smeared on decode. Shape + position keywords parsed.

fixes77: CSS animations
Linear ping-pong animation player on top of fixes73 rotation. Wiggle, swing, and full 0°→359° spin.

fixes79b: PNG transparency
QuickTime Graphics Importer feeding the NetSurf image content handler. PNG + GIF + BMP, all with real transparency.

fixes136: word-break / overflow-wrap
word-break: break-all, keep-all, white-space: nowrap, legacy word-wrap: break-word. URL-style aggressive wrapping.

fixes147: stacking contexts
CSS 2.1 painting order. Opacity, transforms, and explicit z-index all create new stacking contexts, properly painted on real hardware.

fixes151: CSS Grid column placement
grid-column: span N, 1 / -1 full-row hero, positional start / end, span + auto-wrap. Real Grid layout on OS 9.

v1.0: Showcase
The new tool-belt toolbar, razor-sharp URL field, and matted icons rendering home.macsurf.org on a G3 iMac running OS 9.2.2. Native HTTPS via macTLS direct to the origin, server-rendered portal, true-colour images end to end.

The pieces

ComponentLanguagePurpose

browser/
C (C89, CW8)
NetSurf fork with a macos9 frontend. Carbon for the UI, QuickDraw for drawing, Open Transport for networking, Duktape for JS.

proxy/
Go (stdlib only)
The old TLS-stripping HTTP proxy. Largely retired now that macTLS works natively, but still useful as a fallback or on machines without CarbonLib. Mac sends plain HTTP, proxy fetches via HTTPS, returns plain HTTP.

macTLSsibling repo
C (CW8)
Native TLS 1.2 library for OS 9 — modern HTTPS straight from the Mac, no proxy required. BearSSL underneath, 121 trust anchors baked in.

What works today

Rendering pipeline

Full NetSurf fetch → parse → cascade → layout → plot
Native libcss with var() resolution
QuickDraw plotters with an offscreen GWorld back-buffer

CSS — around 150 properties consumed in layout

Custom properties and var()
Flex: justify-content, align-content, order
Grid V1 plus grid-template-columns/rows, gap
border-radius, box-shadow, opacity
Linear and radial gradients
text-shadow, text-overflow: ellipsis
transform (rotate, translate, scale)
z-index stacking contexts (CSS 2.1 painting order)
CSS counters, viewport units, aspect-ratio
Font-family aliases for sans, serif, monospace

Full CSS status →

JavaScript — Duktape 2.7.0, full ES5

Closures, prototypes, regex, JSON
Promises (polyfill), recursion, Mandelbrot
About 6 seconds for ackermann(3,7) on a 233 MHz G3

Images — all five formats

PNG with real per-pixel alpha (lodepng + CopyMask)
GIF with palette transparency
JPEG, BMP, TIFF

Networking

Open Transport TCP, plain non-InContext calls
HTTP/1.1 + chunked + keep-alive + 3xx follow
Connection pooling, 15-second no-progress timeout
HTTPS via macTLS (default) or the Go proxy (fallback)

Browser chrome

Address bar, back / forward / reload / home
Status bar, page-info, multi-window
Smooth scroll bar, keyboard scrolling

Download
Latest is MacSurf v1.3.1 — Forward, refined (2026-05-29): multi-curve ECDHE in TLS 1.3. X25519, P-256, P-384 all offered in supported_groups, with HelloRetryRequest handled cleanly so NIST-only servers like 68kmla.org can pick a curve and drive the rekey — the forum now renders fully on a G3 iMac via TLS 1.3 + P-384. Predecessor v1.3 "Forward" shipped the first native TLS 1.3 on Classic Mac OS; v1.2 "Sealed" closed the entropy hole and wired POST forms + the download manager; v1.0 "Showcase" was the chrome-redesign release; v0.6.2 "Speed-Run" was the cold-load speedup (mactrove.com 30+s → ~2-3s); first numbered alpha at v0.1a1.

MacSurf.sit — the v1.3.1 binary, ready to run. Expand on Mac OS 9.1+ with CarbonLib 1.5+ and launch.
Building from source: clone the repo, then on the Mac side open browser/netsurf/frontends/macos9/MacSurf.mcp in CodeWarrior 8 and choose Build. v1.3.1 is a transparent macTLS engine upgrade — no MacSurf project file changes vs v1.3, just rebuild against the updated macTLS tree. v1.3 builders pulling onto a v1.2 workspace need to add four macTLS files to enable TLS 1.3: bearssl/src/ec/ec_c25519_m15.c, os9/ostls_tls13_keysched.c, os9/ostls_tls13_record.c, os9/ostls_tls13_handshake.c. v1.2 builders on a 1.0 workspace need to add desktop/download.c to the project file list. The earliest release also ships a BuildPack.sit snapshot with the CW8 project pre-wired, but current builds work straight from a fresh clone.

Earlier alpha notes if you want context: docs/release-notes/MacSurf-0.1a1.md.

Getting started

Building the browser
MacSurf is built on Mac OS 9 with CodeWarrior 8 Pro (8.3 update). The source is cross-compile-clean against Retro68 PowerPC GCC, which is what we use for fast Linux-side syntax checks.

Mac-side build guide
Linux cross-dev workflow

Running the proxy
A single Go binary. No config files. No dependencies beyond stdlib.
cd proxy
go build -o macsurf-proxy
./macsurf-proxy

About

A modern web browser for Classic Mac OS 9 PowerPC. Real CSS3, ES5 JavaScript, native HTTPS — built with CodeWarrior on the Carbon API.

macsurf.org

Topics

javascript

css3

duktape

web-browser

powerpc

macintosh

quickdraw

carbon-api

codewarrior

retro-computing

bearssl

netsurf

open-transport

mac-os-9

classic-mac

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MacSurf is presented as a modern web browser designed specifically for Classic Mac OS 9 PowerPC systems. The project aims to bring modern web standards, such as CSS3, ES5 JavaScript, and native HTTPS capabilities, to this legacy hardware, developed using tools like CodeWarrior and the Carbon API. Although currently in an early alpha stage, the project demonstrates significant progress, offering a foundation for exploring the limits of web rendering on vintage systems. The development philosophy centers on making the modern web accessible on machines like a G3 or G4, addressing the issue that modern web features often outpaced the capabilities of Classic Mac OS.

The core functionality of MacSurf relies on a specific technological stack. The browser itself is built in C89, utilizing the Carbon API for the user interface, QuickDraw for rendering, and Open Transport for networking. A critical component is the macTLS library, which provides a native implementation of TLS 1.2, leveraging the BearSSL stack with 121 trust anchors baked into the binary, thereby enabling native HTTPS communication without relying on external proxies. This development has progressed to support TLS 1.3, incorporating multi-curve ECDHE support, including X25519, secp256r1, and secp384r1, which allows it to interface with modern security protocols.

The rendering pipeline integrates native CSS layouts, which has been substantially enhanced through iterative development. MacSurf successfully implements features like CSS Grid, CSS custom properties with variable resolution, transforms (rotate, scale, translate), layout properties such as Flexbox alignment, and advanced styling like box-shadow and gradients. Furthermore, the project successfully incorporates real-time JavaScript execution using Duktape 2.7.0, enabling complex logic involving closures, prototypes, regular expressions, and the implementation of Promises. Image handling is also a feature, with support for rendering PNGs with per-pixel alpha, GIFs, JPEGs, BMPs, and TIFFs.

The evolutionary progression of MacSurf highlights specific milestones in feature implementation. Early versions focused on foundational elements like executing JavaScript on Mac OS 9 and implementing native CSS transforms and radial gradients. Subsequent versions focused on advanced layout structures, such as implementing CSS Grid positioning and stacking contexts based on CSS 2.1 painting order, as well as handling modern text layout features like word-break and overflow wrapping. Recent updates, such as version 1.3.1, focused heavily on advancing the networking layer by incorporating native TLS 1.3 features, ensuring secure, direct communication with the web, which was previously dependent on external proxy methods.

The project’s architecture includes a separate Go binary acting as an HTTP proxy, although the native macTLS implementation has largely superseded the need for this external component. The build process involves cross-compilation against the Retro68 PowerPC GCC, which contributes to the project's cross-platform nature. In summary, MacSurf represents an ambitious effort to merge modern web technologies with the constraints of legacy hardware, demonstrating success in implementing a rich set of web standards directly on Classic Mac OS 9 with native security and layout capabilities.